alpha-Aminobutyric acid

α-Aminobutyric acid

Names
IUPAC name 2-Aminobutanoic acid
Other names 2-Aminobutyric acid; α-Aminobutanoic acid; Ethylglycine; Homoalanine
Identifiers
CAS Number	2835-81-6
3D model (JSmol)	Interactive image
ChEBI	CHEBI:35621
ChEMBL	ChEMBL55242
ChemSpider	6405
ECHA InfoCard	100.018.742
PubChem CID	6657
UNII	8306QPJ19P
CompTox Dashboard (EPA)	DTXSID90862679
InChI InChI=1S/C4H9NO2/c1-2-3(5)4(6)7/h3H,2,5H2,1H3,(H,6,7) Key: QWCKQJZIFLGMSD-UHFFFAOYSA-N InChI=1/C4H9NO2/c1-2-3(5)4(6)7/h3H,2,5H2,1H3,(H,6,7) Key: QWCKQJZIFLGMSD-UHFFFAOYAG
SMILES O=C(O)C(N)CC
Properties
Chemical formula	C4H9NO2
Molar mass	103.12 g/mol
Acidity (pKa)	2.55 (carboxyl), 9.60 (amino)[1]
Magnetic susceptibility (χ)	-62.1·10−6 cm3/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

α-Aminobutyric acid (AABA), also known as homoalanine in biochemistry, is a non-proteinogenic alpha amino acid with chemical formula C₄H₉NO₂. The straight two carbon side chain is one carbon longer than alanine, hence the prefix homo-.

Homoalanine is biosynthesised by transaminating oxobutyrate, a metabolite in isoleucine biosynthesis. It is used by nonribosomal peptide synthases. One example of a nonribosomal peptide containing homoalanine is ophthalmic acid, which was first isolated from calf lens.

α-Aminobutyric acid is one of the three isomers of aminobutyric acid. The two other are the neurotransmitter γ-Aminobutyric acid (GABA) and β-Aminobutyric acid (BABA) which is known for inducing plant disease resistance.

References